This invention relates to a supporting device for a marine propulsion apparatus and more particularly to an improved supporting arrangement for a marine propulsion apparatus that permits a wider variety in the selection in the movement of the propulsion device relative to the associated watercraft.
It is well known to mount a marine outboard drive, such as an outboard motor, for movement relative to the transom of an associated watercraft between a plurality of trim adjusted positions and a tilted up out of the water condition. The simplest of such supporting arrangements comprises a single pivot pin about which the outboard drive pivots. Although such arrangements have the advantages of simplicity, they do present certain disadvantages. For example, the range of movement of the outboard drive is limited by the single pivot point and the outboard drive swings through a substantially greater arc than is necessary in order to tilt the outboard drive up to its out of the water position.
There have been proposed, therefore, systems wherein the outboard drive is supported by means of a pair of links so as to permit the same degree of vertical movement while limiting the amount of longitudinal movement of the outboard drive. Such an arrangement is shown in copending application Ser. No. 672,410, filed Nov. 16, 1984, entitled "Tilting Device For Outboard Engine", filed in the names of Ryoji Nakahama and Toshiyuki Yamazaki and assigned to the assignee of this application. Such systems have a substantial advantage in their operation. However, the optimum location traced by the propulsion unit depends on a wide variety of factors and a fixed double pivot arrangement as shown in that application may not be optimum for all of these applications.
It is, therefore, a principal object of this invention to provide an improved supporting device for a marine propulsion apparatus.
It is a further object of this invention to provide a supporting device for a marine propulsion apparatus that permits adjustment in the locus of movement of the outboard drive during its movement from its normal running condition through its trim adjusted positions to its tilted up out of the water condition.
It is a still further object of this invention to provide an improved linkage system for such a suspension arrangement that will achieve compact movement and which offers the desired adjustability.
Frequently, there are provided one or more fluid motors for achieving the movement of the outboard drive between its trim adjusted position and its tilted up position. Such fluid power assisted devices offer ease of operation, particularly when dealing with high horsepower or high power output systems. Of course, the aforenoted disadvantages are also present in such systems. Therefore, it is a still further object of this invention to provide an improved arrangement for supporting an outboard drive that is moved between its trim and tilt positions by a fluid motor and wherein the locus of movement can be easily and conveniently adjusted.